title: Tuneable Gaussian to flat-top resonator by amplitude beam shaping.
abstract: We outline a simple laser cavity comprising an opaque ring and a circular aperture that is capable of producing spatially tuneable laser modes, from a Gaussian beam to a Flat-top beam. The tuneability is achieved by varying the diameter of the aperture and thus requires no realignment of the cavity. We demonstrate this principle using a digital laser with an intra-cavity spatial light modulator, and confirm the predicted properties of the resonator experimentally.
authors.forename: Sandile
authors.initials: S
authors.lastname: Ngcobo
authors.forename: Kamel
authors.initials: K
authors.lastname: Ait-Ameur
authors.forename: Igor
authors.initials: I
authors.lastname: Litvin
authors.forename: Abdelkrim
authors.initials: A
authors.lastname: Hasnaoui
authors.forename: Andrew
authors.initials: A
authors.lastname: Forbes